docs: def __is_gsi_maintenance_window(table_name, gsi_name, maintenance_windows):
      """ Checks that the current time is within the maintenance window
  
      :type table_name: str
      :param table_name: Name of the DynamoDB table
      :type gsi_name: str
      :param gsi_name: Name of the GSI
      :type maintenance_windows: str
      :param maintenance_windows: Example: '00:00-01:00,10:00-11:00'
      :returns: bool -- True if within maintenance window
      """
      # Example string '00:00-01:00,10:00-11:00'
      maintenance_window_list = []
      for window in maintenance_windows.split(','):
          try:
              start, end = window.split('-', 1)
          except ValueError:
              logger.error(
                  '{0} - GSI: {1} - '
                  'Malformatted maintenance window'.format(table_name, gsi_name))
              return False
  
          maintenance_window_list.append((start, end))
  
      now = datetime.datetime.utcnow().strftime('%H%M')
      for maintenance_window in maintenance_window_list:
          start = ''.join(maintenance_window[0].split(':'))
          end = ''.join(maintenance_window[1].split(':'))
          if now >= start and now <= end:
              return True
  
      return False